An insurgent ambush in eastern Afghanistan has left six U.S. and three Afghan soldiers dead.

The attack is the deadliest against U.S. troops this year, and has made 2007 the deadliest year in Afghanistan for American forces since the 2001 invasion.

At least 101 U.S. troops have been killed in Afghanistan this year.

In comparison, 71 Canadian soldiers and one diplomat have died since 2002, but the U.S. has at least six times the number of troops operating in Afghanistan that Canada does.

The U.S. troops had been returning on foot from a meeting with village elders in Nuristan province late Friday when they were attacked with rocket-propelled grenades and gunfire, Lt. Col. David Accetta told The Associated Press.

"They were attacked from several enemy positions at the same time," said Accetta, a spokesman for NATO's International Security Assistance Force and the U.S. military. "It was a complex ambush."

Besides the dead, eight American and 11 Afghan soldiers were wounded.

"With Sunday being Veterans Day, this is a reminder of the sacrifices that our troops and our Afghan partners make for the peace and stability of the Afghan people," Accetta said.

Mohammad Daoud Nadim, Nuristan deputy police chief, said the ambush happened in Waygal district, about 60 kilometres from the Pakistan border.

Foreign fighters -- Arabs, Chechens and Uzbeks -- are known to operate in the area, but Tamin Nuristani, the region's governor, blamed the Taliban.

Nuristan has seen some heavy fighting in recent months. However, this has been a violent year in Afghanistan. More than 5,800 people -- mostly militants -- have died in insurgency-related violence, according to a count from AP based on figures from Afghan and Western officials.

With files from The Associated Press